This invention relates to metal mold exchanging apparatus for use in an injection molding machine, and more particularly an injection molding machine of the horizontal mold clamping type in which the metal molds are opened and closed in the horizontal direction and the metal molds are loaded and unloaded from the injection molding machine from one side thereof.
In prior art metal mold exchanging apparatus of the type described above, as shown in FIG. 24, a plurality of injection molding machines 1 are juxtaposed in their longitudinal directions, rails 2 are installed on one side of the injection molding machines and the metal molds are exchanged by a single metal mold exchanging machine 3 running on the rails 2. Alternatively, as shown in FIG. 25, a plurality of injection molding machines 1 are juxtaposed in their width direction, a metal mold exchanging machine 3 is installed for each or two injection molding machines, and the loading and unloading of metal mold 4 are performed from one side of each injection molding machine.
In the series type prior art mold exchange machine shown in FIG. 24, it is necessary to separate adjacent injection molding machines by a definite spacing .sub.1 for facilitating maintenance of the injection molding machines 1 so that the total length of a series of injection molding machines becomes long with the result that when automating raw material supply the length of conveyance of the raw material becomes unequal.
Furthermore as shown in FIG. 24 it is necessary to provide transfer rollers 5 for metal mold 4 between the metal mold exchanging machine 3 and the injection molding machine 1, which not only increases the total length of the injection molding machine installation, but also increases the floor space of the installation.
Where metal mold 4 is required to be preheated, it is necessary to install a preheating device 6 between adjacent injection molding machines 1. Moreover, in accordance with the process administration of each injection molding machine it is necessary to perform various process steps in a predetermined manner such as conveyance of the metal mold 4 to the preheating device 6, initiation and termination of the heating, conveyance of the mold exchanging machine 3, movement of the injection molding machine and exchange of the metal mold, which complicates the operation and requires a space for the preheating device 5. Moreover it is difficult to change the layout of the machines.
In the prior art parallel type metal mold exchanging apparatus shown in FIG. 25, it is not easy to automate the entire molding factory, especially when the metal mold 4 is conveyed to the metal mold exchanging apparatus with a crane. Where the metal mold 4 is conveyed with a carriage 7 as shown in FIG. 25, it is not only difficult to automatically transfer the metal mold from the carriage 7 to the metal mold exchanging apparatus 3 but also difficult to automatically control the carriage 7. Furthermore, where the carriages 7 are used, it is necessary to parallelly position the carriages on the sides of the metal mold exchanging apparatus 3 opposite to the molding machines so that it is necessary to increase the distance .sub.2 between adjacent molding machines, thus increasing the entire floor space.
Furthermore, as the metal mold exchanging apparatus are spaced in the longitudinal direction of the injection molding machines by a distance between a position to which a used (old) metal mold is brought and a position to which a new metal mold to be used next is brought (see FIG. 8), where metal molds are transferred along rails, it is not only expensive but also the control of transfer is difficult. Moreover, change of the machine layout is not easy because of a complicated foundation work. It has been proposed to fix the metal mold exchanging apparatus 3 to the floor surface so as to move only the upper portion of the metal mold exchanging apparatus. Although this construction is of relatively low cost, since the metal mold exchanging apparatus is moved to the injection side, the metal mold exchanging apparatus interferes the movement of the injection molding machine.